When some men turn 50, they start to wonder about their legacy: Tony Blair has done little else for the past three years. But among the famous names celebrating their 50th birthdays this year there are a few who have no need to wonder, since it has long been obvious why we will remember them for good or ill. They include Donny Osmond ('Puppy Love'), Osama bin Laden (terrorist mayhem) and - born on 1 April 1957 - David Ivon Gower.

'The sun scarcely graced the English cricket summer with its presence in 1978, but when it did it seemed to adorn the blond head of David Gower,' Wisden rhapsodised the next spring, anointing him as one of its five cricketers of the year. 'The young Leicestershire left-hander could do little wrong. He typified a new, precocious breed of stroke-players, imperious and exciting, who added colour and glamour to an otherwise bedraggled English summer.'

Nearly three decades on, that remains a fair summary of the Gower legacy. It was established on a sunlit afternoon at Edgbaston in June 1978 with his very first ball in Test cricket, which the fluffy-haired novice pulled nonchalantly to the square-leg boundary. For the next 15 years he beguiled and enchanted, a cavalier in an age of roundheads, an artist among craftsmen. His place in the cricketing pantheon ought to be secure.

But is it? The other day I watched a new DVD in which Allan Border and Ian Botham take us through highlights from Ashes matches. An innocent observer would infer from it that Gower's contribution to English cricket in the 1980s was far less memorable or significant than, say, that of Chris Broad or Tim Robinson. In three hours we get the merest glimpse of him at the crease.

Apt enough, some would say. 'Not another bloody Gower cameo!' was often the despairing cry from fans and critics alike, as he scored an exquisite 35 before swishing absent-mindedly at a ball well outside off stump and steering it into the grateful hands of gully. 'I don't know why I got caught in the gully off wide deliveries more than Boycott did,' he wrote in his autobiography. 'Probably because it was more in my nature and probably because the two previous wide ones had been pinged through extra cover and I enjoyed the feeling enough to try it again.'

The crucial word there is 'enjoyed': Gower is an unashamed pleasure-seeker in both cricket and life. At King's School, Canterbury, he lost his house-monitor status for skipping roll-call to take a girl to a James Bond film; as England captain in 1989 he repeated the offence by walking out half-way through a press conference to catch a production of the musical Anything Goes. He hurtled down the Cresta Run, wrote off a hire car on a frozen lake and - most notoriously - buzzed an England tour match against Queensland in a rented Tiger Moth biplane during the winter of 1990-91. This earned him a £1,000 fine and banishment from all the next summer's Tests against West Indies.

For by then the England team had come under the command of two Stakhanovite sergeant majors, Graham Gooch and Micky Stewart. They were infuriated by the golden boy's reluctance to enter into the spirit of the new regime - early nights, press-ups, cold showers. Gower was even chided for wearing blue socks with his cricket whites - further evidence of a fundamental lack of seriousness. 'It seemed to annoy both of them,' he observed, 'that I could succeed without conforming to the methods they laid down.' His relaxed charm and knowing smile compounded the offence. 'I've never been one to mope around looking miserable after losing,' he said. Gooch, by contrast, would mope around looking miserable even after winning. In his Eeyore-ish fashion, he grumbled that 'all Gower had to give was his great talent'.

Quite a big 'all', he might have added. At Old Trafford in July 1992, recalled to the England side after 17 months' absence, Gower surpassed Geoffrey Boycott's career total of 8,114 Test runs with an ethereal drive through the covers that made him the highest-scoring Test batsman in English history. ('Boycott later wrung Gower's hand twice, once for television, once for the press cameras,' the late Ian Wooldridge reported in the Daily Mail, 'and neither time quite hard enough to crush his fingers.') Yet although he retired with a Test average of 44.25, he has never quite escaped a reputation as an underachiever, a bit of a dilettante.

His admirers must share some of the blame here, since the phrases with which they have evoked his style - languid brilliance, casual panache, lazy elegance - all include adjectives that can be taken down and used by the prosecution. It is tempting simply to cite the figures above and have the case thrown out of court, but the temptation should be resisted. For the accusation is, essentially, that Gower wasn't a grafter, and to this he should plead guilty. In the words of the veteran cricket writer John Woodcock: 'Boycott was dedicated to the making of runs; Gower is just as determined to smell the roses.'

With a dogged accumulator such as Boycott, his career statistics are the whole story. With Gower, however mountainous the statistics, they are a footnote - useful ammunition against the charge of dilettantism, perhaps, but almost incidental to how we judge and remember him. He was an artist of the floating world, as other artists understood. When the selectors omitted Gower from the party to tour India and Sri Lanka in the winter of 1992, Harold Pinter sent him a telegram expressing disgust at their 'disgraceful' myopia. Alan Ross, the poet and former Observer cricket correspondent, wrote of Gower: 'He and the bowler are accomplices in a kind of illusory magic.' No one ever said that of Dermot Reeve.

Gower's bat was thin enough to pass for a magic wand. He had it shaved to reduce the weight to 2lb 8oz, more than half a pound lighter than those preferred by most Test batsmen at the time, so he could lift it more quickly and play the ball later: hence the unhurried rhythm of his exquisite late cut, the flowing arc of his cover drive.

But that technical adjustment can't begin to explain his 'illusory magic'. Even left-handedness (as a batsman at least: he does everything else right-handed) isn't a sufficient explanation. Although graceful strokeplay is sometimes thought to be the prerogative of left-handers - Frank Woolley, Frank Worrell, Garry Sobers, Graeme Pollock, Neil Harvey, Brian Lara - plenty of right-handed batsmen have also achieved effortless elegance, from Tom Graveney to Gundappa Viswanath, Viv Richards to Mark Waugh.

Here's the truth: le style, c'est l'homme même. Gower's talent sprang from his nature. Throughout his career there was a continual murmur from malcontents demanding why he couldn't be more like someone else - John Edrich, perhaps. You might as well ask why Cristiano Ronaldo can't be more like Gary Neville. If Gower hadn't been the chap who sabotaged his chances of becoming head boy at school by taking a girl to the pictures, he wouldn't have been the free spirit who pulled his first ball in Test cricket to the fence in front of the Rae Bank Stand. As Neville Cardus wrote of Frank Woolley: 'One thinks of him as a butterfly in a city street on a summer's day.'

Woolley, who played for England from 1909 to 1934, was born in Kent, like Gower. And, like Gower, he was sometimes accused of being casual and careless, often by the same people who praised his poetry and poise. In another essay on Woolley, Cardus quoted the Victorian writer George Meredith:

Lovely are the curves of the white owl sweeping, Wavy in the dusk lit by one large star.

Cardus admitted that cricket had nothing to do with owls or stars. Nevertheless, he explained: 'I am trying to describe an experience of the fancy: I am talking of cadences, of dying falls common to all the beauty of the world.' Gower is one of the few cricketers of the modern age to whom one can apply the word 'cadences' without sounding ridiculous. When I watched him batting, my thoughts often turned to WB Yeats's poem 'An Irish Airman Foresees His Death':

Woolley hit a century before lunch at the age of 47, for Kent against Leicestershire, and played first-class cricket until he was 51. Although Gower is still remarkably fit - at his house in Hampshire, where he lives with his wife and two daughters, he has a gym, spa and tennis court - there is no chance of persuading him to emulate Woolley by swapping his Sky Sports shirt for that of Hampshire, or Leicestershire, or England. He seems content with his lot, presenting TV coverage of the World Cup as he celebrates his 50th birthday.

But he deserves a present. In France, as Sergeant Bilko used to say, they'd name a park after him. Why hasn't Tony Blair awarded knighthoods to Gower and his great contemporary Ian Botham? True, neither of them has donated money to the Labour Party. But they have given the rest of us something far more valuable: the knowledge that occasional exasperation is the price we pay for flickering but indelible moments of pure delight.